Foliar chemistry and standing folivory of early and late-successional species in a Bornean rainforest

Abstract

Background: Few studies have investigated the chemical, morphological and physiological foliar traits and the intensity of standing folivory in a representative set of species of tropical rainforests including species of different successional stages.

Aims: (i) To quantify leaf elemental composition, leaf phenolics and tannin concentrations, physical leaf traits and the intensity of standing folivory in a representative set of species of different successional stages in a Bornean tropical rainforest, and (ii) to investigate the relationships among leaf traits and between leaf traits and accumulated standing folivory.

Methods: Analyses of leaf elemental concentrations, phenolics (Ph) and tannin (Tan) concentrations, leaf mass area (LMA), C assimilation rate and accumulated standing folivory in 88 common rainforest species of Borneo.

Results and Conclusions: Accumulated standing folivory was correlated with the scores of the first axis of the elemental concentrations principal component analysis (mainly loaded by K and C:K and N:K ratios) with lower accumulated standing folivory at high leaf K concentrations (R = –0.33, P = 0.0016). The results show that consistent with growth rate hypothesis, fast-growing pioneer species have lower leaf N:P ratios than late-successional species, that species with higher leaf N concentration have lower LMA according with the ‘leaf economics spectrum’ hypothesis, and that species with lower leaf nutrient concentration allocate more C to leaf phenolics. This study also shows that species with different ecological roles have different biogeochemical ‘niches’ assessed as foliar elemental composition.

Keywords:

• biogeochemical niche
• ecological stoichiometry
• foliar elemental concentration
• growth rate hypothesis
• herbivory
• leaf mass area
• N:P
• phenolics
• rainforest
• tannins
• successional stages
• trace elements

Acknowledgements

This research was supported by the Spanish Government projects CGC2010-17172 and Consolider Ingenio Montes (CSD2008-00040), by the Catalan Government project SGR 2009-458 and by the Estonian Ministry of Education Research (grant SF1090065s07). We thank Theodore Garland Jr for providing the statistical programs used for phylogenetic analyses. We thank the Malaysian and Sabah Governments for their permission to conduct research in Malaysia; Waidi Sinun of Yayasan Sabah and his staff and Glen Reynolds of the Royal Society's South East Asian Rainforest Research Programme and his staff for logistical support at the Danum Valley Field Centre; the Danum Valley Management Committee for full approval and support of the research; the University Malaysia Sabah for cooperation; the UK NERC OP3/ACES research programme for logistical and infrastructure support. This is paper number SEARRP 521 of the Royal Society's South East Asian Rainforest Research Programme.